Visceral leishmaniasis (commonly known as Kala-azar) is a significant health problem in India caused by the parasite Leishmania donovani. Researchers from the Institute of Microbial Technology (CSIR-IMTech), Chandigarh, have identified a unique mechanism by which the parasite suppresses the host immune response.
“An important factor for disease development is suppression of host immunity, which is partly because a specific group of immune cells called ‘dendritic cells’ fail to travel to a host immune activation site known as ‘lymph nodes’ upon infection,” says Dr Pradip Sen, the lead researcher.
Kala-azar is most common in Bihar, Jharkhand, Uttar Pradesh, Kerala, Sikkim and West Bengal. In 1920, Upendranath Brahmachari discovered urea stibamine, which revolutionized the treatment of Kala-azar with over 90% cure rate and minimal side effects.
“Currently, there is no effective vaccine against Kala-azar and the treatment is entirely dependent on chemotherapeutics such as sodium antimony gluconate, miltefosine, and amphotericin B,” Dr Sen informs.
Visceral leishmaniasis (commonly known as Kala-azar) is a significant health problem in India caused by the parasite Leishmania donovani. Researchers from the Institute of Microbial Technology (CSIR-IMTech), Chandigarh, have identified a unique mechanism by which the parasite suppresses the host immune response.
The recent emergence of drug-unresponsive cases highlights the need for a new therapeutic strategy to combat the disease. The researchers have found new treatment targets to reduce the parasites’ inhibitory influence on dendritic cell migration, which may improve immunity against the parasite.
“Our findings reveal that the parasite inhibits dendritic cell migration to lymph nodes by lowering the expression of a receptor protein (CLEC-2) on dendritic cell surface. It mediates this inhibitory effect through two proteins in dendritic cells. Blocking the activity of either of these two proteins increased the expression of receptor protein on dendritic cells and enhanced subsequent dendritic cell arrival to lymph nodes,” Dr Sen explains.
The findings of the study may help improve the host immune response against visceral leishmaniasis. However, the researchers recommend more investigations to confirm the possibility.
The study was conducted with funding support from the Science and Engineering Research Board (SERB), The Department of Science and Technology (DST), and the Council of Scientific and Industrial Research (CSIR).
Besides Dr Pardip Sen, the team comprised Manisha Yadav, Md. Naushad Akhtar, Manish Mishra, Sandeep Kumar, Raj Kumar, Shubham, and Anil Nandal. The article has been published in Microbiology Spectrum, the journal of the American Society for Microbiology.
India Science Wire
ISW/SM/CSIR-IMTECH/Microbiology/Eng/18/05/2023
